A typical multi-phase power supply system is configured to control multiple power channels. More specifically, a power supply controller would be configured to generate multiple control signals or phases. Each of the control signals is assignable and configured to control a corresponding power channel. That is, one control signal would control one power channel. As such, the traditional application of a pure N-phase switching mode power supply controller uses “N” MOSFET drivers to control “N” power channels.
In the traditional switching mode power supply configuration, a multi-phase power controller is designed to generate multiple control signals. Each additional control signal requires additional circuitry used to provide the appropriate control signal for supplying power. For instance, a pulse width modulator (PWM) circuit is required to provide a PWM control signal to manipulate the switching of the control signal.
As power circuits increasingly are tasked to deliver higher power, and to provided increased power control over a broader range of power delivered, this requires additional power channels that are controlled by the same power controller. Under the traditional multi-phase power supply configuration, this would require additional circuitry to generate additional power control signals in order to control the additional power channels.
However, the cost for including additional circuitry, such as PWM circuits, may be too high. For instance, the additional circuitry would require additional space on an integrated circuit when the goal is to reduce the size of the IC chip. Also, additional components included in the added circuitry will have characteristics that are not repeatable from component to component. As such, the control signals generated may be different characteristics, such as, response times. Such differences will detrimentally affect the load currents, or power supplied to the load.
Accordingly, it is desired to have a power controller that is capable of controlling an increased number of power channels without a corresponding increase in the number of components required to generate control signals controlling the power channels.